It seems you like the idea of being a trainer far more than the reality of it.
Yeah... "he destroyed his ball" is the lamest excuse for not training that I've heard in a while.
Lobo, if you're so interested in training dogs, why are you not working with your own dog every day? When I was a kid, I was obsessed with training, grooming and playing with the family dog. I wanted a GSD but she was a little Terrier mix of some kind, so I simply pretended she was a GSD.
I taught her many tricks and had a lot of fun doing it.